Power transmission system



May 17, 1938. F. JANSA POWER TRANSMISSION SYSTEM Filed larch 20, 1937 Til INF] Current I Y mJ V EL /0 m m It F UNITED STATES PATENT OFFICE POWER TRANSMISSION SYSTEM Frantisek Janna, Prague, Czechoslovakia, assignor to Westinghouse Electric 8; Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application March 20. I937, Serial No. 132,056 In Caechoslovakia March 26, 1936 7 Claims. (Cl. 290-16) This invention relates, generally. to power objects of the invention, reference may be had transmission systems and, more particularly, to to the following detailed description taken in the electric transmission of the power of a comconjunction with the accompanying drawing, in bustion engine to the driving wheels of a vehicle. which:

; In previously known systems for the electric Figure 1 is a diagrammatic view of a power systransmission of power on vehicles with combustem embodying the invention, and tion engines of medium horse power capacity Fig. 2 is a view of curves showing operating generators having counter compound and shunt characteristics of certain machines utilized in excitation and utilized to supply electric current the system illustrated in Fig. 1.

0 to the driving motors. A generator of this type Referring to the drawing, a generator G, driven is particularly suited to meet the requirement by a combustion engine or prime mover, supof constant output within a wide range of load plies power to a traction motor M. The main current and with only slight variation in the current from the generator armature i flows engine speed because of its drooping voltage through an interpole winding 2, counter com- .5 characteristic. In order to obtain accelerating pound fleld coils 3 on the main poles of the gencurrent of suflicient magnitude, it is necessary erator, then to the traction motor M, its interto provide such a generator with an additional poles 4 and armature 5, series field coils 6 and field winding which compensates for the dethence through a field reversing switch I back magnetizing effect of the counter compound to the armature of the generator.

turns until the generator voltage rises to a value The generator shunt field winding on the main 20 at which its own shunt excitation is sumcient. poles of the generator consists of two parts 8 However, the additional field must be excited and 9, both wound in the same direction and permanently to prevent a change of polarity of connected in series, a resistor it being connected the generator. in the shunt iiield circuit. During the operation In systems known so far, the power for the of the vehicle, the part 9 is permanently connect- 25 excitation of the additional field winding is fured to a storage battery ll through a regulating nished by separate sources, such as an auxiliary resistor I2. I motor generator or a storage battery, the charg- In this manner the part 9 of the shunt field ing of which must also be provided for. winding is separately excited by current from 0 An object of the present invention is to simthe battery Ill during the acceleration of the plify the generator in a power system of the vehicle. After a certain voltage has been atforegoing type by omitting the additional field tained in the armature of the generator and winding and utilizing a part of the generator the drop across the said part 9 of the shunt field shunt field winding to perform the function oi winding becomes greater than the battery voltthe former, age, the current in the battery reverses and the 35 Another object of the invention is to provide battery is then charged by a portion of the exfor charging the storage battery, which is utilized citing current of the generator. The separate to energize a portion of the generator shunt field excitation during accelerating periods and the winding during acceleration of the vehicle, while charging current when the vehicle is running the vehicle is in operation. can be adjusted by means of the variable resis- 40 Other objects of the invention will be extor l2. plained fully hereinafter or will be apparent to Referring to Fig. 2, which shows the main opthose skilled in the art. erating curves of the electric transmission of According to one embodiment of the invention, power when the shunt field winding of the gena part of thegenerator shunt field winding is erator is connected in accordance with the pres- 5 permanently connected to a storage battery durent invention, it will be seen that the charactering operation of the vehicle in order that the istic curve has the same desirable shape as known battery supplies current for separate excitation with electric transmissions which employ canof the generator during acceleration periods and, siderably more complicated and heavier equipwhen the vehicle is running, the battery is automent to obtain such results. In Fig. 2 are plotted 50 matically charged by a portion of the exciting the terminal voltages E1, E2, E3 and E4 of the current of the generator, thereby making it ungenerator, which correspond to the generator necessary to provide a separate battery charging speeds m, m, m, and m, against the armature device. current I. The curves N1, Na, Na and N4 repre- For a fuller understanding of the nature and sent the relation of the voltage E and current I 55 to give constant output of the engine at speeds m, m, m, and n4. Theintersections of the corresponding E and N curves give the operating points of the engine-generator set.

The performance described in the foregoing applies to full fuel injection of the engine. The curves show that the connection in accordance with the present invention makes it possible to automatically maintain the electric output, volts times current, of the generator almost constant and that this is being obtained by means of equipment, which, compared with known arrangements, is much simpler and lighter.

Therefore, the invention provides a novel connection for automatic control of the output of a power system with an electric transmission according to which a part of the exciting current of the generator is used to charge the battery while the vehicle is running, this battery being utilized to supply power for the separate excitation of the generator during acceleration of the vehicle. The battery can also be used for other purposes, such as lighting and starting, thereby.

making it unnecessary to provide separate sources for such purposes.

Since numerous changes may be made in the above-described construction, and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all matter contained in the foregoing description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. In a power system for a self-propelled vehicle, in combination, a combustion engine, a generator driven by the engine, a shunt field winding for said generator, a storage battery for energizing a part of said shunt field winding during acceleration of the vehicle, and means for adjusting the energizing current supplied by said storage battery.

2. In a power system for a self-propelled ve hicle, in combination, a combustion engine, a generator driven by the engine, a shunt field Winding for said generator, and a storage bat tery for energizing a part only of said shunt field winding during acceleration of the vehicle.

3. In a power system for a self-propelled vehicle, in combination, a combustion engine, a generator driven by the engine, a shunt field Winding for said generator, a storage battery for energizing a part only of said shunt field Winding during acceleration of the vehicle, and

a variable resistor disposed-in the battery circuit for adjusting the energizing current supplied by said storage battery.

4. In a power system for a self-propelled vehicle, in combination, a combustion engine, a generator driven by the engine, a shunt field winding for said generator, and a storage battery permanently connected across a part of said shunt field winding, whereby said battery separately excites the generator during acceleration of the vehicle and is charged by a portion of the exciting current of the generator while the vehicle is running.

5. In a power system for a self-propelled vehicle, in combination, a combustion engine, a generator driven by the engine, a shunt field winding for said generator, 9. storage battery permanently connected across a part of said shunt field winding, whereby said battery separately excites the generator during acceleration of the vehicle and is charged by a portion of the exciting current of the generator while the vehicle is running, and a regulating resistor connected in the battery circuit for adjusting the separate excitation during acceleration and the charging current when the vehicle is running.

6. In a power system for a self-propelled vehicle, in combination, a combustion engine, a generator driven by the engine, said generator having a counter compound field winding and a shunt field winding, and a storage battery permanently connected across a part of said shunt field winding, whereby said part of the shunt iield winding is separately excited by the battery during acceleration of the vehicle and the battery is charged by a portion of the exciting current of the generator while the vehicle is running.

7. In a power system for a self-propelled vehicle, in combination, a. combustion. engine, a generator driven by the engine, said generator having a counter compound field winding and a shunt field winding, a storage battery permanently connected across a part of said shunt field winding, whereby said part of the shunt field winding is separately excited by the battery during acceleration of the vehicle and the battery is charged by a portion of the exciting current of the generator while the vehicle is running, and a variable resistor connected in the battery circuit for regulating the exciting current acceleration and the charging current when the vehicle is running.

FRANTISEK JANSA. 

